The way to true mysticism leads up through rational thought to deep experience of the world and of our will-to-live. We must all venture once more to be "thinkers," so as to reach mysticism, which is the only direct and the only profound world-view. We must all wander in the field of knowledge to the point where knowledge passes over into experience of the world. We must all, through thought, become religious.
This rational thought must become the prevailing force among us, for all the valuable ideas that we need develop out of it. In no other fire than that of the mysticism of reverence for life can the broken sword of idealism be forged anew.

Kulturphilosophie (1923) - Vol. 2 : Civilization and Ethics